Len Deighton - 'Goodbye Mickey Mouse', P-51's in europe.(Bit too much love interest for some though).
Elleston Trevor - 'Squadron Airborne', BoB action. Out of print but available second hand from Amazon.
Derek Robinson-Everything he's written, really!
If you can get hold of it, 'The Stories of Flying Officer X' by H.E. Bates is a classic collection of short stories,
'633 Squadron' by Frederick E Smith is also a classic and 1000% better than the film.
All the other books I have are historical or biographical I'm afraid.